update citation (#281)

README.md

@@ -94,7 +94,7 @@ Please cite this software in your work as:
 ```
 @misc{diskann-github,
    author = {Simhadri, Harsha Vardhan and Krishnaswamy, Ravishankar and Srinivasa, Gopal and Subramanya, Suhas Jayaram and Antonijevic, Andrija and Pryce, Dax and Kaczynski, David and Williams, Shane and Gollapudi, Siddarth and Sivashankar, Varun and Karia, Neel and Singh, Aditi and Jaiswal, Shikhar and Mahapatro, Neelam and Adams, Philip and Tower, Bryan}},
-   title = {{DiskANN: Scalable, efficient and Feature-rich ANNS}},
+   title = {{DiskANN: Graph-structured Indices for Scalable, Fast, Fresh and Filtered Approximate Nearest Neighbor Search}},
    url = {https://github.com/Microsoft/DiskANN},
    version = {0.5},
    year = {2023}